round by Barnaul, Irkutsk, Nerchinsk, Pekin, Shanghai, and Port Blair, whereas over the East India Islands, New Zealand, Tasmania, Australia, Mauritius, and the east of Africa, so far as observations supply information, pressure was under the average, and very largely so over the whole of the southern portions of this wide-spread region. Between the high pressure of the North Atlantic and the relatively high pressure of Southern Asia, there was interposed an extensive tract of low pressure, stretching from Portugal to the Yenisei, and from Egypt to the North Cape, having its centre o°244 inch below the average near Moscow. To the east of the Ural Mountains temperature rose to 4°3 above the average; but on the west side of this depression temperature was 50 at Warsaw and 8°.5 at Kem, west of the White Sea, below the average of July. A striking feature of the distribution of the earth's atmosphere in July 1878, is the enormous breadths over which pressure was below the average, and the comparatively restricted regions over which it stood above the average. An explanation of this seeming anomaly is furnished however by the figures on the map for July, which presents for the first time a monthly mean for the centre of the Pacific Ocean. This mean is from the Sandwich Islands, and shows an excess there above the normal for July, amounting to the large figure of 0.300 inch. tion; and he has the heartiest wishes of all for its more complete extension over British North America, South America, Africa, and among the islands of the Pacific. WILLIAM SHARPEY M.D., F.R.S. DR. R. SHARPEY, whose death we regret to announce took place on Sunday, was born April 1, 1802. He entered on the study of medicine at the University of Edinburgh in 1818. In the autumn of 1822 he came to London, where he spent three months in dissecting, and then proceeded to Paris, and occupied the following winter in the study of clinical medicine and surgery in the hospitals. In 1823 he graduated in Edinburgh, and subsequently was for a short time engaged in the practice of his profession in his native town, Arbroath. Soon afterwards he appears to have changed the plan of his life, and for the purpose of educating himself for the scientific career which he had resolved to adopt, he proceeded to the Continent. After spending several months, which were devoted to general culture, at Rome, Naples, and Florence, he resumed the study of anatomy at Pavia, under Panizza. The following years were spent partly in Edinburgh, partly in Paris, Vienna, Heidelberg, and Berlin. At Berlin he became the pupil and friend of Rudolphi, and by laborious anatomical studies laid the foundation of his future success and eminence. In 1831 he began to lecture in Edinburgh on anatomy, having his friend Prof. Allen Thomson as his associate; and in Thus then the meteorology of the globe for July 1878, 1836 was invited by the Council of the University of stands out as a singular phenomenon, characterised by London, now University College, to accept the Chair of these broad features, viz. :-(1) a greatly reduced pressure Anatomy and Physiology, which he occupied until 1874. over a large portion of the Southern Hemisphere as com- It was about this time that he was most actively pared with what usually obtains there in the winter month engaged in physiological investigation. His scientific of July; (2) a much greater diminution of the pressure writings, which were not numerous, have the characteristic than usually takes place in the summer month of July excellences of accuracy of observation and soundness of over the land of the Northern Hemisphere, over North judgment. One of his earliest contributions was on America, over Central and Eastern Europe, Western and ciliary motion, and appeared in 1830. Others formed the Central Siberia; and (3) a much larger increase of pressure subjects of articles in the "Cyclopædia of Anatomy and than usually occurs in the Northern Hemisphere over the Physiology," while a still greater number were embodied great oceans in July, the area of unusually high pressure in the successive editions of the "Elements of Anatomy." being extended, as regards the Atlantic to the north-east as Notwithstanding the rapid progress of anatomical and far as Christiansund, and as regards the Pacific to west-physiological science during the past thirty years, none ward over Central and Southern Asia, as far as the of Dr. Sharpey's observations have lost their value. Arabian Sea. It may be worth remarking that this increased pressure over the oceans and diminished pressure over the land of the Northern Hemisphere is in accordance with what might be expected to result from an increased solar radiation; whilst on the other hand the increased pressure over Southern and Central Asia, and diminished pressure in the Southern Hemisphere, is not in direct accordance with this supposition. The point here referred to will however receive an illustration from subsequent numbers of the Weather Maps, by which it is probable that different results as regards the states of the atmosphere will appear, with the varying states of the sun from year to year. The future maps of this international series will be eagerly scanned in connection with many of the larger questions of atmospheric physics, as well as those directly practical questions of climate with which we have been almost exclusively concerned in this article. It is plain that we need not hope to succeed in dealing with most of the larger problems proposed by meteorology without the help of the data laid before us in so full and convenient a form by the International Weather Maps of General Myer. It is only thus that we can trace to their proximate causes such climatal phenomena as the recurring droughts of India and the cold, sunless summer of the British Islands in 1879, and show their true relations to the great movements of the atmosphere. For this great work the highest praise must be conceded to General Myer, whose genius struck out this cosmopolitan scheme of observation, and whose powers of organisation and determination of will bore down all obstacles which stood in the way of its realisa He was appointed Secretary of the Royal Society in 1854, shortly after important changes had taken place in its administration, in the bringing about of which he, with others whose names are not less distinguished, had taken part. The beneficial effect of these changes in extending the Society's influence for the advancement of natural science was due in great measure to the sagacity and energy with which he administered such of its affairs as fell within the scope of his duties-duties for which he was singularly fitted by the extent and variety of his learning, by the wisdom of his counsels, by the wide range of his scientific interests, by the candour and justice which guided him in appreciating other men's work, and by his ready sympathy with every true and honest worker. Great as Dr. Sharpey's services to science were in his public capacities as Secretary of the Royal Society, as a Member of the Senate of the University, and of the Royal Commission on Science, and in other ways, these were perhaps not the most important. For years he was the greatest teacher of anatomy and physiology in this country, occupying a position side by side with Johannes Müller in Germany. Just as the influence of Johannes Müller's life and teaching is still powerful in that of his pupils, so we may confidently anticipate that Sharpey's work will follow him. Of the fellow-workers in his own field who are at this moment mourning his loss there is perhaps not one who does not directly or indirectly owe him that which has made him what he is; nor should we be far wrong if we were to add that those who are best endowed owe him most. While the very sounds of our friend's voice are freshly DEEP-SEA DREDGING AND LIFE IN THE THE representatives floating or swimming near the ocean surface. The deep-sea sea-anemonies are represented on the surface by floating sea-anemonies. There are surfaceworms, hydroids, bryozoa, barnacles, and fish represented by close allies on the deep-sea bottom. Lastly, there are abundance of surface Rhizopoda corresponding with the vast quantities of them below (Fig. 10). Friday Evening Lecture delivered at the Royal Institution on March 5, by H. N. Moseley, F.R.S., Assistant Registrar of the University of London. Continued from p. 547 not only to Globigerinæ, but to all the vast pelagic fauna to which I have referred. Do the jelly-fish, the crustacea, the mollusca, and other animals so abundant in surface waters inhabit also the depths of the mid-ocean, or is there a vast azoic area between the surface and the bottom untenanted by life in any SV form? To this question we can at present return no answer of any value. The trawls used by the Challenger swept, in going down to the bottom and coming up again, the whole stretch of the sea from top to bottom, and it is impossible to tell whether pelagic animals found in it when it reached the surface were caught there or at the bottom. Mr. Murray used the towing-net at various depths, but the same objection applies to the results. Deep-sea Medusæ have been described by Prof. Haeckel and deep-see Siphonophora by Prof. Studer, but both may have come from very small depths. What is wanted to determine the problem is a net which can be let down to any required depth, securely closed, then be opened and towed for some time, then closed again and brought to the surface. Its contents would then be certainly derived from the depth at which it was towed. I devised, some months ago, a net which will, I believe, answer these requirements. Its mouth, which is fastened on a hinged frame, is kept shut by means of springs, but can be opened by the action of a pair of electromagnets excited by a battery on board FIG. 11.-Arenaceous Rhizopoda. a, Astrorhiza catenata, 2,760 fathoms; b, Sorosphæra confusa, 900 to 2,900 fathoms; c, Hyperammina vagars attached to a piece of shell, 2,000 fathoms. (After H. B. Brady, F.R.S., Quart. Journ, Micro. Sci., vol. xix., new series). ship. A rope is used to tow the net, which contains an insulated wire. Whilst the net is being towed, the magnets are maintained in action and keep its mouth open. As soon as the net is to be drawn to the surface the current is stopped, and the net closes. Mr. Agassiz intends to use this net or some better contrivance during this summer on the American coast, and we may await the results with great interest.1 It has long been known that pelagic animals change their level constantly, appearing sometimes in swarms at the very surface of the sea, and again disappearing. Some come up in calm weather, others only at night, but it is quite uncertain to what depths they descend. Probably the different pelagic animals vary very much in this respect, and they may each have their definite zones of range. It would be most interesting to learn the exact habits of such animals as Pteropods in this matter. The question could easily be determined by the use of such a net as I have described for a short period at any one locality, and most valuable results might be obtained by any one who cared to take the matter up in the neighbourhood of our own coasts. Very possibly the pelagic animals do not range to any great depth, 100 or 150 fathoms, or less. Prof. Weissman concludes from his researches at Lake Constance that the surface animals there sink to a depth of about 50 feet in the day-time in order to escape the sunlight, and rise slowly in the evening, following the rising limit of darkness in the water. It is quite possible that a vast stretch of water between the surface and the bottom is nearly or absolutely without life. There are a large number of animals, some of the most curious forms, which most probably do not live at the bottom of the sea, but which constantly appeared in our trawl-net when used in great depths. Amongst these are a large number of fish of great rarity. They may have come from 20 fathoms or from 2,000. We cannot tell. Possibly they live at 60 or 100 fathoms, and rarely reach the surface; hence their scarcity. Some certainly pelagic animals, which are very scarce, probably live at a considerable depth from the surface. Here (Fig. 12) is a very scarce animal indeed, a pelagic Nemertine worm. The Nemertines mostly live on the seabottom, and are long and worm-like. This is one which has become so modified to live a pelagic existence as to resemble them in appearance very little. Its body has 1 Since this lecture was sent to the printers I have heard from Mr. Agassiz that Capt. Sigsbee has invented a net which he expects will do all that is wanted with complete efficiency. FIG. 12.1-Pelagonemertes Rollestoni. On the left the proboscis sheath with the proboscis coiled up inside. men of this animal was found in the trawl after it had been down to 1,800 fathoms, to the south of Australia. Another was got off Japan when the net had been down to 755 fathoms. The animal was only found on these two occasions at these widely distant spots. Fifty years ago Lesson, on the voyage of the Coquille, found in abundance, on the sea-surface between the Moluccas and New the sea surface when young in all the pleasures of warmth and sunlight, sink when fully grown to lead a sluggish life on the cold and dismal bottom. Here (Fig. 13) is a remarkable deep-sea fish. It is nearly allied to the Angler of our aquariams. It was found dead off the Greenland coast, but closely similar fish were obtained by the Challenger in great depths down to 2,400 fathoms all over the world. Mr. Agassiz also got plenty of them. The fish has a very near ally which lives on the surface amongst the gulf weed, from which it builds curious ball-like nests. You see the fish has no ventral fins, and must be, like its surface relative, a very feeble swimmer. It has very small eyes and a huge mouth, and on the top of its head is a lure set on a movable stalk, with which, like the Angler, it attracts its prey within reach of its mouth. The fish is black all over, as are most deep-sea fish, except on the lure. This is composed of numerous tentacle-like branches, which are covered with white spots, probably phosphorescent, when the animal is living. At the bases of the branches are two horn-like appendages which are white, probably also phosphorescent. The fish most likely thus manufactures its own light, whilst its tentacles, spangled with bright spots, swayed to and fro, no doubt lure many a victim to destruction. This fish is sixteen inches in actual length. Here (Fig. 14) is what Prof. Lütken, from whom these figures are taken,' believes to be the young of this curious epochs, we should expect to find in its vast area many remnants of the fauna of that age and of subsequent geological epochs; and such was the conclusion of the late Prof. Agassiz, and of many other naturalists. It was expected that all kinds of ancient forms would be brought up by the deep-sea net. Contrary to anticipation, the deep-sea fauna is mainly composed of more or less modern shallow-water genera and their allies. The fish of the deep sea comprise amongst them no Dipnoi, no Ganoids, and no lampreys; they are allies of the cod, the salmon, and the Angler. There are no Trilobites in the deep sea, and no Graptolites, no Bellemnites. All the most ancient forms which now survive occur in shallow water. Lingula, most ancient of all, is abundant in two or three feet of water, and has, I believe, never been found below ten fathoms. Trigonia and Limulus survive in shallow water, and so do Amphioxus and Cestracion. Heliopora, the only living representative of a vast number of palæozoic corals, is a shore form. It is true that corals which come within MilneEdwards's definition of the Rugosa occur in deep water, but that group needs great modification, and the structural difference between the deep-sea forms and ordinary Caryophyllias is probably of comparatively little zoological importance. Though stalked Crinoids occur in deep water, they are fish. It was found in the stomach of an Albacore Thynnus, a surface-living predatory fish which was caught in the tropical Atlantic. You see the little fish has, like the adult, no ventral fins. The eye is very much bigger in proportion than in the adult, but that is merely an instance of retention in the young of what has been nearly lost in the adult by disuse. Certain deep-sea blind crustacea similarly have young with fully-developed eyes. The lure on the head is just growing. If the animal is not the young of the species just shown, which probably extends from Greenland to the tropics in the deep sea, it is certainly that of some closely-allied form. The young of other deep-sea fish have been found in the stomachs of Albacores. The young of most shallowwater bottom-living fish, such as the Angler and the flounder, pass their early existence at the sea-surface. If this deep-sea fish really develops in the early stage at the surface, how do the eggs reach the top of the water? Possibly they rise slowly from the bottom. Perhaps some other deep-sea animals go through their early stages at the surface. According to Prof. Geikie the deep ocean basins date from the remotest geological antiquity, and Dr. Carpenter in his late lecture here maintained the same conclusion. Whether such be the case or not, any changes which may have taken place converting deep seas into shallow must have occurred very slowly, so that ample time for migration of deep-sea forms to fresh deep seas must have been afforded. Why is it therefore that very many ancient forms do not occur in the deep sea? If the ancient deep sea had been colonised say in the Silurian or Devonian I "Vidensk. Selsk.-Skr." 5te Række, 11te Bd. v. p. 319. 2 Loc. cit. p. 428. FIG. 15.-Deep-sea Ascidian (Octacnemus Bythius). Above.-The animal viewed from below; of one half the natural size. The nucleus is seen in the centre through the transparent base of the "animal. P, pedicle of attachment; B, exhalant orifice; R, rectum. Below.-Diagrammatic section through the middle line of the animal's body. A, inhalant orifice; M, muscle attached to nucleus; other letters as in figure above. also found in a depth of only forty fathoms. There are a certain number of forms in the deep sea which do not occur now in shallow water, and do occur as fossils in the chalk or elsewhere, but they do not form a very high percentage of the total number. We might have expected to find surviving in the deepsea missing parts of the branches of the zoological family tree, animals of ancient pedigree which might for example have explained the affinities of the Bryozoa or the Brachiopoda, but scarcely a single animal thus of firstrate zoological importance was obtained in great depths. This is a most extraordinary fact, for in our deep-sea dredgings we have explored for the first time nearly threequarters of the earth's surface. The most important new animal, zoologically speaking, obtained from deep water by the Challenger Expedition is, as far as I know, this Ascidian (Fig. 15), which I have named Octacnemus. Most of its body is transparent. It has eight radiate arms. Its viscera are gathered together into a small nuclear mass as in Salpa, but the nerve ganglion lies on the mass. The animal is attached to From H. N. Moseley, "Notes by a Naturalist on the Challenger, p. 588. (Macmillan and Co., 1879.) |